JP5556401B2 - Control device for lubricating oil supply system - Google Patents

Description

  The present invention relates to a control device for a lubricating oil supply system that includes an engine-driven pump driven by an internal combustion engine and circulates the lubricating oil using the driving force of the internal combustion engine. The present invention relates to a control device for a lubricating oil supply system that reduces the driving load of a pump by limiting the amount of circulation of the oil.

  In the lubricating oil supply system described in Patent Document 1, a sub pump having a smaller capacity than the main pump is provided in addition to the main pump. In this lubricating oil supply system, the lubricating oil is circulated by driving the sub pump instead of the main pump when the engine is cold and the demand for the lubricating oil is not so great.

  In this way, when the demand for lubricating oil is small, adopting a configuration in which the lubricating oil is circulated by a small-capacity sub pump, the circulating amount of the lubricating oil is limited to the required amount, and the pump acting on the internal combustion engine It becomes possible to reduce the driving load and suppress the fuel consumption of the internal combustion engine.

  In addition, as a configuration for limiting the circulation amount of the lubricating oil in accordance with the magnitude of the demand for the lubricating oil, the relief pressure of the relief valve provided in the lubricating oil supply passage is changed to It is also possible to adopt a configuration that reduces the driving load of the pump by reducing the relief pressure when demand is small.

JP 2010-24926 A

  By the way, since the engine temperature is low immediately after the engine is started, when the configuration in which the lubricating oil is supplied by the sub pump as described above or the configuration in which the relief pressure is lowered is adopted, the lubricating oil is supplied by the sub pump or the relief pressure Or the circulation amount of the lubricating oil is limited.

  Since the lubricating oil in the supply passage flows out of the supply passage while the engine is stopped, the lubricating oil in the supply passage is often removed when the engine is started. Therefore, when the circulation amount of the lubricating oil is limited as described above at the time of starting the engine, the state in which the oil pressure in the supply passage is relatively low continues. As a result, the lubricating oil does not readily reach the end of the supply passage, and as a result, there is a risk that supply of the lubricating oil will be insufficient in a part of the lubricated part.

  The present invention has been made in view of the above circumstances, and its object is to reduce the drive load of the pump acting on the internal combustion engine as much as possible to suppress the fuel consumption of the internal combustion engine, while supplying the lubricating oil when starting the engine. An object of the present invention is to provide a control device for a lubricating oil supply system capable of suppressing the occurrence of shortage.

In the following, means for achieving the above object and its effects are described.
The invention according to claim 1 is a control device for a lubricating oil supply system that includes an engine-driven pump driven by an internal combustion engine and circulates the lubricating oil using the driving force of the internal combustion engine. the control device of the lubricant supply system running low control that limits the amount of circulating lubricating oil at a small demand to reduce the drive load of the pump acting on the internal combustion engine, before SL internal combustion engine is started A first determination value is set based on the temperature of the engine coolant at the time of starting the engine, and the estimated piston temperature, which is an alternative value of the piston temperature of the internal combustion engine, is greater than or equal to the first determination value. Until this time, the gist is to prohibit the execution of the low-pressure control.

According to the above configuration, the execution of the low pressure control is prohibited until the estimated piston temperature becomes equal to or higher than the first determination value set based on the coolant temperature at the time of starting the engine. Immediately after starting, the amount of circulation is not limited and the lubricating oil is circulated. Therefore, immediately after the engine is started, the hydraulic pressure of the lubricating oil in the supply passage is maintained at a higher level than when low pressure control is executed. As a result, the lubricating oil in the supply passage flows out while the engine is stopped, and even when the engine is started under the condition that no lubricating oil remains in the supply passage, the end of the supply passage is promptly reached. It becomes possible to spread the lubricating oil.

When the temperature of the engine cooling water at the time of starting the engine is low, that is, when it is estimated that the engine temperature at the time of starting the engine is low and the temperature of the lubricating oil is low, the viscosity of the lubricating oil becomes high. It is estimated that When the viscosity of the lubricating oil is high, it is necessary to pump the lubricating oil at a high hydraulic pressure over a longer period in order to reach the lubricating oil to the end of the supply passage.
Further, since the piston of the internal combustion engine is lubricated and cooled by the lubricating oil, the temperature of the piston and the temperature of the lubricating oil have a high correlation.
Therefore , in the first aspect of the invention, the first determination value is set based on the engine coolant temperature at the time of starting the engine, and the piston temperature substitute value having a high correlation with the temperature of the lubricating oil. The execution of the low pressure control is prohibited until the estimated piston temperature is equal to or higher than the first determination value. Therefore, according to the first aspect of the present invention, when it is estimated that the temperature of the lubricating oil is low and the viscosity of the lubricating oil is high, the execution of the low pressure control is prohibited accordingly and the hydraulic pressure of the lubricating oil is increased. The period during which the state is kept relatively high can be lengthened.

  Therefore, it is possible to adjust the length of the period during which the execution of the low pressure control is prohibited according to the viscosity of the lubricating oil, prohibiting the execution of the low pressure control over a longer period than necessary, Even when the lubricating oil cannot be spread to the end, it is possible to suitably suppress the start of the low pressure control.

  That is, according to the first aspect of the present invention, the pump drive load acting on the internal combustion engine is reduced as much as possible to suppress the fuel consumption of the internal combustion engine, while the supply of lubricating oil is insufficient when the engine is started. It becomes possible to suppress this.

  Specifically, as described in claim 2, if the temperature of the engine cooling water at the time of starting the engine is lower, if the first determination value is set to a larger value, As the temperature is lower and the viscosity of the lubricating oil is estimated to be higher, the period during which the low-pressure control is prohibited can be extended.

The invention according to claim 3, in the control device of the lubricant supply system according to claim 1 or claim 2, after the pre-Symbol piston estimated temperature becomes equal to or higher than the first judgment value, the engine cooling water A second determination value is set based on the temperature of the piston, and when the estimated piston temperature value is less than the second determination value, the low pressure control is executed, while the estimated piston temperature value is equal to or greater than the second determination value. It is the gist to perform the hydraulic switching control without executing the low-pressure control when the.

  If low-pressure control for reducing the circulation amount of the lubricating oil is executed, the driving load of the pump can be reduced, so that the fuel consumption of the internal combustion engine can be suppressed. However, if the engine temperature rises excessively due to the limited amount of lubricating oil circulating, each part of the engine will be damaged by heat and the durability of the internal combustion engine will be significantly reduced. It will be.

On the other hand, according to the configuration described in claim 3, the hydraulic pressure switching control based on the estimated piston temperature value after the estimated piston temperature value exceeds the first determination value and the execution of the low pressure control is permitted. When the estimated piston temperature becomes equal to or higher than the second determination value, the low pressure control is not executed.
In the configuration described in claim 3, after the execution of the low pressure control is permitted, the estimated piston temperature is used to estimate the engine temperature. The estimated piston temperature is used here because the piston is easily affected by the heat generated by the combustion in the internal combustion engine, and the temperature management by controlling the circulation amount of the lubricating oil among the components that constitute the internal combustion engine. This is because it is a part of high importance.
Therefore, if the configuration according to claim 3 is adopted , the low-pressure control is stopped before the engine temperature becomes excessively high, the restriction on the circulation amount of the lubricating oil is released, and the circulation amount of the lubricating oil is increased. It becomes possible to suppress the engine temperature from becoming excessively high.

  If it is estimated that the temperature of the engine cooling water is low and the engine cooling water is effectively circulated by the circulation of the engine cooling water, low pressure control is executed to perform lubrication. Even if the oil circulation rate is continuously limited, it is estimated that there is a low possibility that heat damage will occur in various parts of the engine.

  On the other hand, in the invention according to the third aspect, the second determination value, which is a determination value for determining whether or not to execute the low pressure control, is set based on the temperature of the engine cooling water. Therefore, it is possible to determine whether or not the low-pressure control can be performed in accordance with the magnitude of the possibility of thermal damage.

  Specifically, as described in claim 4, when the temperature of the engine cooling water is lower, if the second determination value is set to a larger value, the engine temperature is excessively increased. While suppressing, the fuel consumption of the internal combustion engine can be more preferably suppressed by extending the execution period of the low pressure control as much as possible.

  Note that the higher the amount of heat generated by combustion in the internal combustion engine, the higher the temperature of the piston. That is, the amount of heat generated by combustion in the internal combustion engine and the change in the temperature of the piston have a high correlation.

As described above, the number of fuel strokes per unit time can be estimated by referring to the engine speed, and the amount of heat generated in one combustion stroke can be estimated by referring to the fuel injection amount. Therefore, as described in 請 Motomeko 5, it is preferable to adopt a configuration that calculates the piston temperature estimate based on the engine rotational speed and the fuel injection amount.

If the configuration for calculating the estimated piston temperature based on the engine rotational speed and the fuel injection amount as in the configuration described in claim 5 is adopted, based on the engine rotational speed and the fuel injection amount, The amount of heat generated in the internal combustion engine having a high correlation with the change in the piston temperature can be estimated, and the estimated piston temperature can be calculated based on the estimated amount of heat.

  In the control device for the lubricating oil supply system of the internal combustion engine mounted on the vehicle, the amount of traveling wind introduced into the engine room increases as the vehicle speed increases as the vehicle speed increases. Therefore, the higher the vehicle speed, the higher the cooling effect by the traveling wind, and the engine temperature and the piston temperature are less likely to rise.

Therefore, if a configuration is adopted in which the estimated piston temperature is calculated with reference to the vehicle speed in addition to the engine rotational speed and the fuel injection amount as described in claim 6 , the change in the cooling effect accompanying the change in the vehicle speed can be reduced. In consideration of this, it is possible to calculate an estimated piston temperature value, and it is possible to estimate a change in piston temperature more accurately.

Further, as the temperature of the engine cooling water is lower, the cooling effect by the engine cooling water becomes higher, and the engine temperature and the piston temperature are less likely to rise. Therefore, if a configuration for calculating the estimated piston temperature with reference to the engine cooling water temperature in addition to the engine rotation speed and the fuel injection amount as described in claim 7 is used, the temperature of the engine cooling water is reduced. The piston temperature estimated value can be calculated in consideration of the change in cooling effect accompanying the change, and the change in piston temperature can be estimated more accurately.

Note that when it is determined whether or not to execute the low pressure control based on the estimated piston temperature value, which is an alternative value of the piston temperature, the temperature of other parts of the internal combustion engine is excessively increased. However, if the piston temperature does not rise excessively, the low pressure control will continue. As a result, the engine coolant may boil or damage due to heat may occur in portions other than the piston. Therefore, when it is determined whether or not to execute the low pressure control based on the estimated piston temperature value, as described in claim 8, when the temperature of the engine cooling water is equal to or higher than the upper limit temperature, It is desirable to employ a configuration that prohibits execution of low-pressure control regardless of the magnitude of the estimated piston temperature.

  If such a configuration is adopted, even when the piston temperature is low and the estimated piston temperature value is smaller than the second determination value, the low pressure control is executed when the engine cooling water temperature rises to the upper limit temperature. It is prohibited and the circulation amount of the lubricating oil is increased, so that the increase in the temperature of the internal combustion engine and the temperature of the engine cooling water is suppressed.

As a result, it is possible to suppress the engine cooling water from boiling or the occurrence of heat damage at portions other than the piston.
As a configuration for reducing the driving load of the pump by limiting the circulation amount of the lubricating oil, the relief pressure can be changed in the lubricating oil supply passage as described in claim 9. The structure which provides a valve is employable. By adopting such a configuration, low pressure control can be performed by lowering the relief pressure of the relief valve.

The schematic diagram which shows schematic structure of the lubricating oil supply system concerning one Embodiment of this invention. The schematic diagram explaining the operation | movement aspect in the high relief pressure state of the hydraulic pressure supply system concerning the embodiment. The schematic diagram explaining the operation | movement aspect in the low relief pressure state of the hydraulic pressure supply system concerning the embodiment. The flowchart which shows the flow of a series of processes concerning hydraulic control at the time of starting. Explanatory drawing which shows the relationship between the water temperature at the time of start in the hydraulic control at the time of start, and a 1st determination value, and the relationship between a piston temperature estimated value and the oil pressure of lubricating oil. The flowchart which shows the flow of a series of processes concerning hydraulic pressure switching control. Explanatory drawing which shows the relationship between the water temperature and 2nd determination value in hydraulic pressure switching control, and the relationship between a piston temperature estimated value and the hydraulic pressure of lubricating oil.

  Hereinafter, an embodiment in which a control device for a lubricating oil supply system according to the present invention is embodied as an electronic control device that comprehensively controls an internal combustion engine mounted on a vehicle will be described with reference to FIGS. . FIG. 1 is a schematic diagram showing a schematic configuration of a lubricating oil supply system according to the present embodiment.

  The lubricating oil supply system according to this embodiment includes an engine-driven pump 20 connected to the output shaft 11 of the internal combustion engine 10 as indicated by a broken line in FIG. The lubricating oil supply system according to the present embodiment drives the pump 20 by using the driving force of the internal combustion engine 10, and pumps the lubricating oil stored in the oil pan 22 by the pump 20, thereby providing a lubrication target portion. The lubricating oil is supplied to each part of the internal combustion engine 10.

  As shown in FIG. 1, a supply passage 21 is connected to the pump 20, and lubricating oil stored in an oil pan 22 is supplied to the lubrication target portion through the supply passage 21. Note that the lubricating oil supplied to the lubricated portion of the internal combustion engine 10 and used for lubrication flows down through the internal combustion engine 10 and is stored again in the oil pan 22 attached to the lower portion of the internal combustion engine 10. It has become.

  As shown in FIG. 1, a relief valve 30 is provided in a portion of the supply passage 21 downstream of the pump 20. The relief valve 30 is connected to a reflux passage 23 connected to a portion of the supply passage 21 upstream of the pump 20.

  Thus, when the hydraulic pressure of the lubricating oil in the supply passage 21 becomes equal to or higher than the relief pressure, the relief valve 30 is opened, and a part of the lubricating oil in the supply passage 21 is pumped in the supply passage 21 through the reflux passage 23. It is refluxed to a site upstream of 20.

  As will be described later, the relief valve 30 is configured to change the relief pressure in two stages by controlling the hydraulic pressure switching valve 40. The hydraulic pressure switching valve 40 is driven based on a drive command from the electronic control unit 100 that controls the internal combustion engine 10 in an integrated manner.

  The electronic control unit 100 includes a central processing unit (CPU) that executes arithmetic processing related to the control of the internal combustion engine 10, arithmetic processing related to hydraulic control of the lubricating oil through control of the hydraulic pressure switching valve 40, and the like. The electronic control device 100 also includes a calculation program and calculation map for calculation processing, a read-only memory (ROM) in which various data are stored, a random access memory (RAM) that temporarily stores calculation results, and the like. It has.

  The electronic control unit 100 includes a crank angle sensor 101 that detects an engine rotational speed NE based on the rotation angle of the output shaft 11, and a water temperature TW of engine cooling water that circulates in a water jacket formed inside the internal combustion engine 10. A water temperature sensor 102 to be detected is connected. The electronic control device 100 includes a vehicle speed sensor 103 that detects the vehicle speed V, an air flow meter 104 that detects the intake air amount GA introduced into the internal combustion engine 10, and an accelerator position sensor that detects the amount of operation of the accelerator pedal by the driver. 105 etc. are also connected.

  The electronic control unit 100 captures signals output from these various sensors 101 to 105, performs various calculations related to control of the fuel injection amount Q, ignition timing, and the like based on the captured signals, In order to control the amount of circulation and control the oil pressure and the amount of circulation of the lubricating oil supplied to the internal combustion engine 10 through the supply passage 21, the oil pressure switching valve 40 is operated.

  Hereinafter, the configuration and operation of the relief valve 30 in the lubricating oil supply system according to the present embodiment will be described in more detail with reference to FIGS. 2 and 3 are schematic views showing the configuration of the relief valve 30 in the lubricating oil supply system according to this embodiment, and FIG. 2 shows the state when the relief valve 30 is in a high relief pressure state. FIG. 3 shows a state when the relief valve 30 is in a low relief pressure state.

  As described above, the relief valve 30 is provided in the downstream portion of the supply passage 21 from the pump 20. As shown in FIG. 2, in the relief valve 30, a cylindrical sleeve 31 is accommodated in the housing so as to be slidable in the axial direction. A relief port 32 penetrating the sleeve 31 is formed on the radial side wall of the sleeve 31. Further, inside the sleeve 31, a bottomed cylindrical valve body 35 is accommodated so as to be slidable in the axial direction of the sleeve 31, that is, the vertical direction in FIG.

  A support member 37 is fixed to the bottom surface of the housing of the relief valve 30 in FIG. A compressed spring 36 is accommodated between the support member 37 and the valve body 35. As a result, the valve body 35 is always urged upward by the spring 36 in the direction of closing the relief port 32 in FIG.

  As a result, in the relief valve 30, when the hydraulic pressure of the lubricating oil flowing through the supply passage 21 is increased and the hydraulic pressure acting on the valve body 35 is increased, the valve body 35 is moved to the spring 36 as indicated by an arrow. 2 is displaced downward in FIG. 2 against the urging force, and the relief port 32 is opened.

  As shown on the right side of FIG. 2, the relief port 32 is formed so as to open into the reflux passage 23. Therefore, the supply passage 21 and the return passage 23 are communicated with each other through the relief port 32 by displacing the valve body 35 to the valve opening position, that is, the position at which the relief port 32 is opened.

  When the supply passage 21 and the return passage 23 are communicated with each other through the relief port 32 in this way, a part of the lubricating oil flowing through the supply passage 21 is returned to the upstream side of the pump 20 through the return passage 23. .

  In short, in the relief valve 30, the relief pressure is determined by the magnitude of the urging force of the spring 36. That is, the relief port 32 is opened and flows through the supply passage 21 when the urging force by which the lubricating oil flowing through the supply passage 21 urges the valve body 35 downward in FIG. 2 becomes larger than the urging force of the spring 36. Part of the lubricating oil is returned to the upstream side of the pump 20.

  As shown in the lower part of FIG. 2, a back pressure chamber 38 is formed between the bottom surface 31 a of the sleeve 31 and the bottom surface of the housing to which the support member 37 is fixed. A part of the lubricating oil flowing through the supply passage 21 is guided to the back pressure chamber 38 through the branch passage 41 and the back pressure passage 42.

  As described above, the sleeve 31 is supported in the housing of the relief valve 30 so as to be slidable in the axial direction thereof. As a result, in the relief valve 30, due to the hydraulic pressure acting on the bottom surface 31a of the sleeve 31, the biasing force biasing the sleeve 31 upward in FIG. 2 and the hydraulic pressure acting on the top surface 31b. The sleeve 31 is displaced in the vertical direction within the housing in accordance with the magnitude relationship with the force that urges the sleeve 31 downward.

  The shape of the sleeve 31 is designed so that the area of the bottom surface 31a where the hydraulic pressure in the back pressure chamber 38 acts is larger than the area of the top surface 31b where the hydraulic pressure of the lubricating oil flowing through the supply passage 21 acts. ing. Therefore, when the back pressure chamber 38 is communicated with the supply passage 21 through the branch passage 41 and the back pressure passage 42 and the same hydraulic pressure is applied to the bottom surface 31a and the top surface 31b of the sleeve 31, the pressure receiving area of the bottom surface 31a is reduced. The force for biasing the sleeve 31 upward is increased by an amount larger than the pressure receiving area of the top surface 31b.

As a result, the sleeve 31 is displaced upward, and is positioned upward in the housing as shown in FIG.
As shown on the left side of FIG. 2, a hydraulic pressure switching valve 40 is provided between the branch passage 41 connected to the supply passage 21 and the back pressure passage 42 connected to the back pressure chamber 38. A drain passage 43 is further connected to the hydraulic pressure switching valve 40. The hydraulic pressure switching valve 40 is connected to the branch passage 41 and the back pressure passage 42 as shown in FIG. As described above, the state in which the back pressure passage 42 and the drain passage 43 communicate with each other can be switched.

  The drain passage 43 is connected to a portion upstream of the pump 20 in the supply passage 21, and the back pressure chamber is switched when the hydraulic pressure switching valve 40 is switched to a state in which the back pressure passage 42 and the drain passage 43 communicate with each other. The lubricating oil in 38 is recirculated to a portion upstream of the pump 20 in the supply passage 21.

  In the lubricating oil supply system of the present embodiment, the relief pressure is changed by controlling the oil pressure in the back pressure chamber 38 by operating the oil pressure switching valve 40 and changing the position of the sleeve 31 in the housing. To do.

  Specifically, as shown in FIG. 3, the hydraulic pressure switching valve 40 is operated so that the branch passage 41 and the back pressure passage 42 communicate with each other, and a part of the lubricating oil in the supply passage 21 is transferred to the back pressure chamber 38. When introduced, a hydraulic pressure equal to the hydraulic pressure of the lubricating oil in the supply passage 21 acts on the bottom surface 31 a of the sleeve 31.

  As a result, the force that urges the sleeve 31 upward in FIG. 3 due to the hydraulic pressure acting on the bottom surface 31a of the sleeve 31 causes the sleeve 31 to move toward the top surface 31b of the sleeve 31 in FIG. The force is greater than the downward biasing force, and the sleeve 31 is displaced upward to be positioned above the housing of the relief valve 30 as shown in FIG.

  On the other hand, when the hydraulic pressure switching valve 40 is operated so as to connect the back pressure passage 42 and the drain passage 43 as shown in FIG. 2, the lubricating oil in the back pressure chamber 38 is supplied through the drain passage 43. 21 is returned to the upstream side of the pump 20 and the hydraulic pressure in the back pressure chamber 38 is reduced.

  As a result, the force that urges the sleeve 31 downward in FIG. 2 due to the hydraulic pressure acting on the top surface 31b of the sleeve 31 causes the sleeve 31 to move toward the bottom surface 31a of the sleeve 31 due to the hydraulic pressure acting on the sleeve 31 in FIG. Since the force is greater than the upward biasing force, the sleeve 31 is displaced downward to be positioned below the housing of the relief valve 30 as shown in FIG.

  In this way, when the sleeve 31 is positioned downward in the housing, the valve body 35 is moved to the valve opening position as compared with the case where the sleeve 31 is positioned upward as shown in FIG. The amount of compression of the spring 36 increases. That is, at this time, the urging force received by the valve body 35 from the spring 36 is larger than when the sleeve 31 is positioned above, and the hydraulic pressure of the lubricating oil in the supply passage 21 when the relief port 32 is opened. That is, the relief pressure increases.

  On the other hand, as shown in FIG. 3, when the sleeve 31 is positioned upward in the housing, the valve body 35 is displaced to the valve opening position as compared with the case where the sleeve 31 is positioned downward. The amount of compression of the spring 36 is reduced. That is, at this time, the urging force received by the valve body 35 from the spring 36 is smaller than when the sleeve 31 is positioned below, and the relief pressure is lowered.

  As described above, according to the lubricating oil supply system of the present embodiment, the hydraulic pressure switching valve 40 is operated to control the hydraulic pressure in the back pressure chamber 38, and the sleeve 31 is displaced in the expansion and contraction direction of the spring 36. It is possible to switch between a high relief pressure state where the pressure increases (state shown in FIG. 2) and a low relief pressure state where the relief pressure becomes low (state shown in FIG. 3).

  In the lubricating oil supply system of the present embodiment, the magnitude of the demand for lubricating oil in the internal combustion engine 10 is estimated based on the coolant temperature TW and the like of the engine cooling water. Low pressure control is performed to switch the valve 40 to a low relief pressure state.

  Thus, when the demand for lubricating oil is small, if the low pressure control is performed to switch to the low relief pressure state and reduce the hydraulic pressure of the lubricating oil flowing in the supply passage 21, the circulation amount of the lubricating oil is limited, and the internal combustion engine Therefore, the fuel consumption of the internal combustion engine 10 can be suppressed by reducing the driving load of the pump 20 acting on the engine 10. That is, the circulation amount of the lubricating oil is limited in accordance with the necessary amount, and excessive driving of the pump 20 due to the pumping of the lubricating oil more than necessary is suppressed, so that fuel can be saved.

  In addition, when the internal combustion engine 10 is not warmed up, when the engine is cold, low pressure control is performed to reduce the pressure of the lubricating oil used for cooling each part of the engine. As a result, the temperature of each part of the engine quickly rises due to the combustion heat of the internal combustion engine 10, and the warm-up can be completed early.

  By the way, the lubricating oil in the supply passage 21 flows out of the supply passage 21 while the engine is stopped. For this reason, the lubricating oil in the supply passage 21 is often removed when the engine is started.

  Thus, when the supply passage 21 is not filled with the lubricating oil and the low-pressure control is executed and the circulation amount of the lubricating oil is limited, the lubricating oil does not easily reach the end of the supply passage 21. Therefore, there is a possibility that insufficient supply of lubricating oil may occur in a part of the lubricated part.

  Therefore, in the lubricating oil supply system of the present embodiment, the start time hydraulic control that temporarily prohibits the execution of the low pressure control is executed immediately after the engine is started. Hereinafter, the hydraulic control of the lubricating oil in the lubricating oil supply system according to the present embodiment will be described with reference to FIGS.

  FIG. 4 is a flowchart showing a flow of a series of processes relating to the start time hydraulic control executed when the engine is started. This start time hydraulic control is executed by the electronic control unit 100 every time the engine is started.

  When the start time hydraulic control is executed as shown in FIG. 4, the electronic control unit 100 first refers to the start time water temperature TWst, which is the water temperature TW of the engine cooling water when the engine start is started, in step S100. The first determination value X is set based on the starting water temperature TWst. The first determination value X is set to a larger value as the starting water temperature TWst is lower, as shown in FIG.

  When the first determination value X is set based on the starting water temperature TWst in this way, the process proceeds to step S110, and the electronic control unit 100 estimates the oil temperature of the lubricating oil circulating in the internal combustion engine 10 in order to estimate the oil temperature of the internal combustion engine. A piston temperature estimated value A, which is an alternative value of the temperature of 10 pistons, is calculated.

  Here, in order to estimate the oil temperature of the lubricating oil, the piston temperature estimated value A is calculated because the piston is lubricated and cooled by the lubricating oil, and the piston temperature and the lubricating oil temperature have a high correlation. Because it is.

  The estimated piston temperature A is based on the engine heat speed NE, the fuel injection amount Q, the vehicle speed V, and the water temperature TW based on the amount of heat generated by combustion in the internal combustion engine 10 and the amount of heat lost by cooling with engine cooling water and traveling wind. It is calculated by estimating.

  Specifically, the estimated piston temperature A is calculated using the relationship shown in the following mathematical formula.

上記の数式における始動時水温ＴＷｓｔを変数とする関数ｆ（ＴＷｓｔ）は機関始動時のピストン温度を示す関数である。すなわち、機関始動時の機関温度並びにピストンの温度は始動時水温ＴＷｓｔと略等しい温度になっていることが推定されるため、ここでは始動時水温ＴＷｓｔに基づいて機関始動時のピストンの温度を推定するようにしている。

The function f (TWst) having the starting water temperature TWst as a variable in the above formula is a function indicating the piston temperature at the time of engine starting. That is, since it is estimated that the engine temperature at the time of starting the engine and the temperature of the piston are substantially equal to the water temperature TWst at the time of starting, here, the temperature of the piston at the time of starting the engine is estimated based on the water temperature TWst at the time of starting. Like to do.

  A function f (NE, Q) having the engine speed NE and the fuel injection amount Q as variables in the above formula is a function indicating a temperature change caused by heat generated by combustion in the internal combustion engine 10, and the vehicle speed V is a variable. A function f (V) is a function indicating a temperature change caused by cooling by the traveling wind. In addition, the function f (TW) having the water temperature TW as a variable in the above mathematical formula is a function indicating a temperature change caused by cooling by the engine cooling water.

  Therefore, the integral value of these functions f (NE, Q), f (V), and f (TW) shown in the above formula is the amount of change in the temperature of the piston, and the relationship shown in the above formula is used. By doing so, it is possible to calculate the estimated piston temperature A by adding the value indicating the temperature of the piston at the time of starting the engine and the amount of change in the temperature of the piston.

  The amount of heat generated due to combustion in the internal combustion engine 10 increases as the engine speed NE increases and the number of combustion strokes per unit time increases, and the fuel injection amount Q increases and the amount of fuel injection per one combustion stroke increases. The higher the amount of fuel provided for combustion, the higher. Therefore, the value calculated by the function f (NE, Q) in the above mathematical formula becomes larger as the engine speed NE is higher and as the fuel injection amount Q is larger.

  In addition, the cooling effect by the traveling wind increases as the vehicle speed V increases and more air is introduced into the engine room. Therefore, the value calculated by the function f (NE) in the above mathematical formula becomes larger as the vehicle speed V is higher.

  And the cooling effect by engine cooling water becomes so large that the water temperature TW is low. Therefore, the value calculated by f (TW) in the above mathematical formula becomes larger as the water temperature TW is lower.

  It should be noted that the contents of each function in the above mathematical expression can accurately estimate the temperature of the piston of the internal combustion engine 10 based on the parameters (engine speed NE, fuel injection amount Q, vehicle speed V, water temperature TW). Further, it is set based on the results of experiments and simulations performed in advance.

  When the piston temperature estimated value A is calculated through step S110, the process proceeds to step S120, and the electronic control unit 100 determines whether or not the calculated piston temperature estimated value A is less than the first determination value X.

  When it is determined in step S120 that the estimated piston temperature A is less than the first determination value X (step S120: YES), the process proceeds to step S130, and execution of the low pressure control is prohibited. .

  When the execution of the low pressure control is thus prohibited, the hydraulic pressure switching valve 40 is maintained in a state where the back pressure passage 42 and the drain passage 43 are in communication with each other as shown in FIG. 2, and the lubricating oil supply system is brought into a high relief pressure state. Retained.

  Thus, when the execution of the low pressure control is prohibited through step S130, the process returns to step S110, and the electronic control unit 100 is based on the engine speed NE, the fuel injection amount Q, the vehicle speed V, and the water temperature TW at that time. Then, the estimated piston temperature A is calculated again.

  On the other hand, when it is determined in step S120 that the piston temperature estimated value A is equal to or higher than the first determination value X (step S120: NO), the process proceeds to step S140, and the electronic control unit 100 determines that the low pressure The prohibition of control execution is released, and the execution of low-pressure control is permitted.

  That is, in this starting hydraulic pressure control, the piston temperature estimated value A is repeatedly calculated until the piston temperature estimated value A becomes equal to or higher than the first determination value X, and the piston temperature estimated value A becomes the first determination value X. Execution of low-pressure control is prohibited for less than that. Then, when the estimated piston temperature A becomes equal to or higher than the first determination value X, execution of the low pressure control is permitted.

  As described above, the first determination value X is set to be larger as the starting water temperature TWst is lower. However, the magnitude of each value determined based on the starting water temperature TWst is as follows. Determining that the circulation of the lubricating oil in the high relief pressure state is continued until the lubricating oil reaches the end of the supply passage 21 based on the estimated piston temperature A increasing to the first determination value X or more. Is set based on the results of experiments and simulations performed in advance.

  As a result, the execution of the low pressure control is prohibited until the estimated piston temperature A becomes equal to or higher than the first determination value X through the start time hydraulic control until the lubricating oil reaches the end of the supply passage 21. In the meantime, the high relief pressure state can be continued.

  In step S140, when the execution of the low pressure control is permitted, the electronic control unit 100 ends the start time hydraulic control and starts the hydraulic pressure switching control shown in FIG. FIG. 6 is a flowchart showing a flow of a series of processes related to the hydraulic pressure switching control.

This hydraulic pressure switching control is repeatedly executed at a predetermined control cycle by the electronic control device 100 on condition that the execution of the low pressure control is permitted through the hydraulic pressure control at start-up.
When this hydraulic pressure switching control is started as shown in FIG. 6, the electronic control unit 100 first determines whether or not the water temperature TW is lower than the upper limit temperature TWlim in step S200.

  Note that the upper limit temperature TWlim is such that when the water temperature TW becomes equal to or higher than the upper limit temperature TWlim, the internal combustion engine 10 is damaged due to heat or the engine cooling water is boiled based on the upper limit temperature TWlim. And the magnitude | size is set so that it can be determined that there is a high possibility that the temperature of the internal combustion engine 10 will rise.

  When it is determined in step S200 that the water temperature TW is equal to or higher than the upper limit temperature TWlim (step S200: NO), the process proceeds to step S250, and the electronic control unit 100 does not execute the low pressure control, and the lubricating oil By setting the supply system to a high relief pressure state, the supply amount of the lubricating oil is increased and each part of the engine is cooled.

When the lubricating oil supply system is brought to a high relief pressure state through step S250, the electronic control unit 100 once ends this process.
On the other hand, when it is determined in step S200 that the water temperature TW is lower than the upper limit temperature TWlim (step S200: YES), the process proceeds to step S210, and the electronic control unit 100 detects the water temperature detected by the water temperature sensor 102. With reference to TW, the second determination value Y is set based on the water temperature TW.

The second determination value Y is set to a larger value as the water temperature TW is lower as shown in FIG.
When the second determination value Y is set based on the water temperature TW in this manner, the process proceeds to step S220, and the electronic control unit 100 estimates the piston temperature A as in step S110 in the start time hydraulic control in order to estimate the engine temperature. Is calculated.

  Here, in order to estimate the engine temperature, the piston temperature estimated value A is calculated because the piston is easily affected by the heat generated by the combustion in the internal combustion engine 10, especially among the components constituting the internal combustion engine 10. This is because the temperature management by controlling the circulation amount of the lubricating oil is highly important.

  When the piston temperature estimated value A is calculated through step S220, the process proceeds to step S230, and the electronic control unit 100 determines whether or not the calculated piston temperature estimated value A is less than the second determination value Y.

  When it is determined in step S230 that the estimated piston temperature A is less than the second determination value Y (step S230: YES), the process proceeds to step S240, and the electronic control unit 100 switches the hydraulic pressure. The valve 40 is switched to a state in which the branch passage 41 and the back pressure passage 42 are communicated to execute low pressure control.

When the low pressure control is executed in this way, the electronic control unit 100 once ends the hydraulic pressure switching control.
On the other hand, when it is determined in step S230 that the estimated piston temperature A is equal to or higher than the second determination value Y (step S230: NO), the process proceeds to step S250, and the electronic control unit 100 switches the hydraulic pressure. The valve 40 is switched to a state in which the back pressure passage 42 and the drain passage 43 are communicated to bring the hydraulic pressure supply system into a high relief pressure state.

  As described above, the second determination value Y is set to be larger as the water temperature TW is lower. However, the magnitude of each value determined based on the water temperature TW is an estimated piston temperature value. Based on the fact that A has increased to the second determination value Y or more, it is possible to determine in advance that the temperature of the piston has risen excessively and is approaching a level at which damage due to heat may occur. It is set based on the results of experiments and simulations.

  As described above, in the lubricating oil supply system according to the present embodiment, immediately after the engine is started, the execution of the low pressure control is prohibited until the estimated piston temperature A becomes equal to or higher than the first determination value X through the start time hydraulic control. Become so.

  Accordingly, as shown in FIG. 5, when the estimated piston temperature A is less than the first determination value X, the lubricating oil is supplied in a state where the hydraulic pressure in the supply passage 21 is kept relatively high. It becomes like this.

  For example, as shown in FIG. 5, when the starting water temperature TWst is “T1”, when the estimated piston temperature A is less than the first determination value X, the execution of the low pressure control is prohibited and the supply passage 21 The state where the internal hydraulic pressure is maintained at a relatively high pressure continues. Then, as shown by the arrow in FIG. 5, the estimated piston temperature A increases with engine operation. When the estimated piston temperature A exceeds the first determination value X, the execution of the low pressure control is permitted and the low pressure control is performed. And the hydraulic pressure in the supply passage 21 is reduced.

  Then, after the execution of the low pressure control is permitted through the start time hydraulic control, the hydraulic pressure switching valve 40 is controlled according to the magnitude relationship between the piston temperature estimated value A and the second determination value Y through the hydraulic pressure switching control. become.

  Accordingly, as shown in FIG. 7, when the estimated piston temperature A is less than the second determination value Y, the low pressure control is executed and the hydraulic pressure in the supply passage 21 is kept low, while the estimated piston temperature is estimated. When the value A is equal to or greater than the second determination value Y, the low pressure control is stopped and the hydraulic pressure in the supply passage 21 is kept high.

  In the hydraulic pressure switching control, it is determined in step S200 whether or not the water temperature TW is lower than the upper limit temperature TWlim. When the water temperature TW is equal to or higher than the upper limit temperature TWlim, the low pressure control is not executed. Therefore, as shown in FIG. 7, when the water temperature TW is equal to or higher than the upper limit temperature TWlim, the hydraulic pressure in the supply passage 21 is always kept high regardless of the magnitude of the estimated piston temperature A.

According to the embodiment described above, the following effects can be obtained.
(1) Execution of the low pressure control is prohibited until the estimated piston temperature A becomes equal to or higher than the first determination value X set based on the starting water temperature TWst. The low pressure control is not executed, and the lubricating oil is circulated without limiting the circulation amount. Therefore, immediately after the engine is started, the hydraulic pressure of the lubricating oil in the supply passage 21 is maintained at a higher level than when low pressure control is executed. As a result, the lubricating oil in the supply passage 21 flows out while the engine is stopped, and even when the engine is started under the condition that no lubricating oil remains in the supply passage 21, the supply passage 21 Lubricating oil can be quickly distributed to the end.

  When the starting water temperature TWst is low, that is, when the engine temperature at the time of starting the engine is low and the temperature of the lubricating oil is estimated to be low, it is estimated that the viscosity of the lubricating oil is high. The When the viscosity of the lubricating oil is high, in order to make the lubricating oil reach the end of the supply passage 21, it is necessary to pump the lubricating oil over a longer period at a high hydraulic pressure. In this regard, in the above embodiment, the first determination value X is set based on the starting water temperature TWst, and the low pressure control is performed until the estimated piston temperature A becomes equal to or higher than the first determination value X. Execution of is prohibited. Therefore, when it is estimated that the temperature of the lubricating oil is low and the viscosity of the lubricating oil is high, execution of the low pressure control can be prohibited and the period during which the hydraulic pressure of the lubricating oil is kept high can be extended.

  Therefore, it is possible to adjust the length of the period during which the execution of the low pressure control is prohibited according to the viscosity of the lubricating oil, prohibiting the execution of the low pressure control over a longer period than necessary, and the supply passage 21. It is possible to suitably suppress the low-pressure control from being started despite the fact that the lubricating oil has not been distributed to the end of the.

  That is, while reducing the drive load of the pump 20 acting on the internal combustion engine 10 as much as possible to suppress the fuel consumption of the internal combustion engine 10, it is possible to suppress the occurrence of insufficient supply of lubricating oil when the engine is started. become able to.

  (2) Since the first determination value X is set to a larger value as the starting water temperature TWst is lower, the temperature of the lubricating oil is lower and the viscosity of the lubricating oil is estimated to be higher. The period during which execution of the low pressure control is prohibited becomes longer. That is, when the temperature of the lubricating oil is low and it is necessary to pump the lubricating oil over a longer period at a high hydraulic pressure in order to reach the end of the supply passage 21, the execution of the low pressure control is prohibited accordingly. The period to do can be lengthened.

  (3) If low-pressure control that reduces the circulation amount of the lubricating oil is executed, the driving load of the pump 20 can be reduced, so that the fuel consumption of the internal combustion engine 10 can be suppressed. However, if the engine temperature rises excessively due to the restriction of the circulation amount of the lubricating oil, each part of the engine is damaged by heat, and the durability of the internal combustion engine 10 is significantly reduced. It will end up.

  On the other hand, in the above embodiment, after the estimated piston temperature A is equal to or higher than the first determination value X and execution of the low pressure control is permitted, the hydraulic pressure switching control based on the estimated piston temperature A is performed. When the piston temperature estimated value A becomes equal to or higher than the second determination value Y, the execution of the low pressure control is prohibited. Therefore, before the engine temperature becomes excessively high, the low-pressure control is stopped, the restriction on the circulation amount of the lubricating oil can be released, the circulation amount of the lubricating oil can be increased, and the engine temperature becomes excessive. It becomes possible to suitably suppress the increase.

  If it is estimated that the engine temperature can be effectively suppressed by circulating the engine cooling water because the water temperature TW is low, low pressure control is executed to circulate the lubricating oil. Even if the engine is continuously limited, it is estimated that there is a low possibility that heat damage will occur in various parts of the engine.

  On the other hand, in the above embodiment, the second determination value Y, which is a determination value for determining whether or not to execute the low pressure control, is set based on the water temperature TW. Whether or not the low-pressure control can be executed can be determined in accordance with the magnitude of the possibility of occurrence of the low pressure.

  (4) Since the second determination value Y is set to a larger value as the water temperature TW is lower, it is preferable to make the execution period of the low pressure control as long as possible while suppressing an excessive increase in the engine temperature. In addition, the fuel consumption of the internal combustion engine 10 can be suppressed.

  (5) The higher the vehicle speed V, the greater the amount of traveling wind introduced into the engine room as the vehicle travels. Therefore, the higher the vehicle speed V, the higher the cooling effect of the traveling wind. The temperature of is difficult to rise.

  In the above embodiment, the amount of heat generated by combustion in the internal combustion engine 10 is estimated based on the engine rotational speed NE and the fuel injection amount Q, and the estimated piston temperature A is calculated with reference to the vehicle speed V. Yes. Therefore, the piston temperature estimated value A can be calculated in consideration of the change in the cooling effect accompanying the change in the vehicle speed V, and the change in the piston temperature can be estimated more accurately.

  (6) Further, as the water temperature TW is lower, the cooling effect by the engine cooling water becomes higher, and the engine temperature and the piston temperature are less likely to rise. Therefore, in the above embodiment, the amount of heat generated by combustion in the internal combustion engine 10 is estimated based on the engine speed NE and the fuel injection amount Q, and the estimated piston temperature A is calculated with reference to the water temperature TW. I have to. Therefore, the piston temperature estimated value A can be calculated in consideration of the change in the cooling effect accompanying the change in the water temperature TW, and the change in the piston temperature can be estimated more accurately.

  (7) As in the above-described embodiment, when it is determined whether or not the low pressure control can be performed based on the estimated piston temperature A that is an alternative value of the piston temperature, the temperatures of other parts of the internal combustion engine 10 are determined. Even if the temperature rises excessively, the low pressure control will continue if the temperature of the piston does not rise excessively. As a result, the engine coolant may boil or damage due to heat may occur in portions other than the piston. On the other hand, in the above embodiment, when the upper limit temperature TWlim is set and the water temperature TW is equal to or higher than the upper limit temperature TWlim, the low pressure control is executed regardless of the magnitude of the estimated piston temperature A. Is prohibited.

  Therefore, even when the piston temperature is low and the estimated piston temperature A is smaller than the second determination value Y, when the water temperature TW rises to the upper limit temperature TWlim, the execution of the low pressure control is prohibited and the lubricating oil Is increased, and the rise in the temperature of the internal combustion engine 10 and the water temperature TW is suppressed.

Thereby, it can suppress that engine cooling water boils or damage by heat generate | occur | produces in parts other than a piston.
In addition, the said embodiment can also be implemented with the following forms which changed this suitably.

  The estimated piston temperature A is calculated for estimating the oil temperature in step S110 as the estimated oil temperature calculating means, and the estimated piston temperature A is used for estimating the engine temperature in step S220 as the estimated engine temperature calculating means. The configuration to calculate is shown. On the other hand, the oil pressure alternative value and the engine temperature alternative value may be calculated separately to execute the start time hydraulic control and the hydraulic pressure switching control.

  That is, an estimated oil temperature value is calculated as an alternative value of the oil temperature in step S110, and it is determined whether or not the estimated oil temperature value is less than the first determination value X in step S120, based on the result. A configuration that determines whether or not the low-pressure control can be executed can also be adopted.

  In step S220, an estimated engine temperature value is calculated as an alternative value for the engine temperature. In step S230, it is determined whether the estimated engine temperature value is less than the second determination value Y. Based on the result. It is also possible to adopt a configuration that executes low-pressure control.

  When calculating the estimated oil temperature or estimated engine temperature, the heat in the internal combustion engine 10 based on the amount of heat generated by combustion and the amount of heat deprived by cooling is calculated in the same manner as the method for calculating the estimated piston temperature A described above. It is desirable to employ a configuration that calculates an estimated oil temperature value or an estimated engine temperature value based on the balance.

  -The specific calculation method of piston temperature estimated value A, oil temperature estimated value, and engine temperature estimated value is not limited to the method shown in the said embodiment. That is, the calculation method of these estimated values can be changed as appropriate.

In the above embodiment, the configuration in which the circulation amount of the lubricating oil is reduced by reducing the relief pressure of the relief valve 30 as the low pressure control has been shown.
On the other hand, as described in Patent Document 1, a sub pump is provided in addition to the main pump, and low pressure control is executed by reducing the circulation amount of the lubricating oil by driving the sub pump instead of the main pump. The present invention can also be applied as a control device for a lubricating oil supply system.

DESCRIPTION OF SYMBOLS 10 ... Internal combustion engine, 11 ... Output shaft, 20 ... Pump, 21 ... Supply passage, 22 ... Oil pan, 23 ... Recirculation passage, 30 ... Relief valve, 31 ... Sleeve, 31a ... Bottom surface, 31b ... Top surface, 32 ... Relief Port, 35 ... Valve body, 36 ... Spring, 37 ... Support member, 38 ... Back pressure chamber, 40 ... Hydraulic pressure switching valve, 41 ... Branch passage, 42 ... Back pressure passage, 43 ... Drain passage, 100 ... Electronic control unit, DESCRIPTION OF SYMBOLS 101 ... Crank angle sensor, 102 ... Water temperature sensor, 103 ... Vehicle speed sensor, 104 ... Air flow meter, 105 ... Accelerator position sensor

Claims (9)

A control device for a lubricating oil supply system that includes an engine driven pump driven by an internal combustion engine and circulates the lubricating oil using the driving force of the internal combustion engine. In a control device for a lubricating oil supply system that executes low pressure control for limiting a circulation amount to reduce a driving load of the pump acting on the internal combustion engine,
When the front SL internal combustion engine is started, and sets the first determination value based on the temperature of the engine cooling water at engine starting, the piston temperature estimate is an alternative value of the temperature of the piston of the internal combustion engine is the same Execution of the low-pressure control is prohibited until the first determination value or more. 2. The control device for a lubricating oil supply system according to claim 1, wherein the first determination value is set to a larger value as the temperature of the engine cooling water at the time of starting the engine is lower. In the control device of the lubricating oil supply system according to claim 1 or 2,
After pre-Symbol piston estimated temperature is equal to or greater than the first determination value, set the second determination value based on the temperature of the engine coolant, the piston temperature estimation value is less than the second determination value The control apparatus for a lubricating oil supply system, wherein the low pressure control is sometimes executed, and when the estimated piston temperature is equal to or higher than the second determination value, hydraulic pressure switching control that does not execute the low pressure control is executed. The control device for a lubricating oil supply system according to claim 3, wherein the second determination value is set to a larger value as the temperature of the engine cooling water is lower. In the control device of the lubricating oil supply system according to any one of claims 1 to 4,
And agencies rotational speed, the control unit of the lubricating oil supply system and calculates the piston temperature estimate based on the fuel injection amount. A control device for a lubricating oil supply system of an internal combustion engine mounted on a vehicle,
In addition to the agencies rotational speed and the fuel injection quantity control device of the lubricant supply system according to claim 5 which calculates the piston temperature estimate with reference to the vehicle speed. In the control device of the lubricating oil supply system according to claim 5 or 6,
In addition to the agencies rotational speed and the fuel injection quantity control device of the lubricating oil supply system with reference to the temperature of the engine coolant and calculates the piston temperature estimate. In the control device of the lubricating oil supply system according to claim 7 ,
When the temperature of the agencies coolant is equal to or greater than the upper limit temperature, the piston regardless of the magnitude of the temperature estimated value, the control unit of the lubricating oil supply system and inhibits the execution of the low-pressure control . With a relief valve that can change the relief pressure in the lubricating oil supply passage,
The control device for a lubricating oil supply system according to any one of claims 1 to 8 , wherein in the low pressure control, a circulation amount of the lubricating oil is limited by lowering a relief pressure of the relief valve.

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